Crushing-mill.



Nu. fi l-LOU. P

T. L. & T. J. STURTEVANT.

CRUSHING MILL.

(Application filed May 18, 1899.)

atented Jan. 23, I900.

(No Model.)

3 Sheets-Sheet l,

Nu. 642,0I7. Patented Ian 23, I900 T. L. & T. J. STURTEVANT. CRUSHINGMILL.

(Application filed May 18, 1899.;

3 Sheets-Sheet 2.

(No Model.)

Patented Jan. 23, I900.

T. L. & T. J. STURTEVANT.

CRUSHING MILL.

(Application filed May 18, 1899.)

3 Sheets-Sheet 3.

(No Model.)

llh STATES PATENT OFFICE.

THOMAS L. STURTEVANT, OF QUINCY, AND THOMAS J'. STURTEVANT, OF NEl/VTON,MASSACHUSETTS.

CRUSHlNG--MILL.

SPECIFICATION formingpart of Letters Patent No. 642,017, dated January23, 1900.

Application filed MaylB, 1899. Serial No. 717,349. (No model.)

To aZZ whom it may concern:

Be it known that we, THOMAS L. STURTE- VANT, residing at Quincy, in thecounty of Norfolk, and Tnonas J. STURTEVANT, residing at Newton, in thecounty of Middlesex, State of Massachusetts, citizens of the UnitedStates, have invented certain new and useful Improvements inCrushing-Mills, of which the following is a specification, referencebeing had therein to the accompanying drawings.

Our invention relates to crushingnnills for pulverizing ore-bearingrocks and the like, and particularly to that type of mill in whichrotary crushing-rolls are used, the material to be reduced being fedfrom a suitable hopper or from feeding-ways between the rolls by whichit is crushed and after pulverization passing out through a suitabledischargeopening in the bottom of the mill-casing.

The main feature of invention of our improved crushing-mill is the novelconstruction of the crushing-rolls, which have as their distinguishingcharacteristics loose movable tires of hard steel which form continuouscircumferential crushing-faces for the rolls, said tires being carriedby flanged hubs mounted on the roll-shafts, radially-movable weights orhammers being arranged inside of the tires between the flanges of thesupporting-hubs, so that when the mill is running the weights will beforced outwardly by centrifugal action and will thus yieldingly pressthe tires together, so as to effectually crush the material. By thisconstruction a certain amount of flexibility, as it were, is given tothe crushing-faces of the rolls, so that much of the strain incident tocrushing is absorbed by the flexible or yielding crushing-faces and lessis transmitted to the shafts. The shocks and stress of crushing are nottherefore thrown so strongly upon the shafts or mill-casing as is thecase where the rolls are unyielding, and this fact enables a lightermill structure to be used than heretofore. At the same time theroll-shafts maybe mounted in fixed bearings and the objections tospringbearings are avoided.

In the accompanying drawings, in which we have shown a mill embodyingour invention, Figure 1 is a side elevation of a mill containing ourimprovements. Fig. 2 is a vertical section of the mill transverse to theshafts, showing the interior construction. Fig. 3 is a vertical sectionon the line 3 3 of Fig. 2. Fig. 4 is a detail sectional view of amodified form of crushing-mill.

Referring to the drawings by letter, A de notes suitable supports forthe lower half of the mill-casing a, which is provided with adischarge-spout, and (1 denotes the upper half of the mill casing, saidpart a being bolted to the part a, as shown in Fig. 1, and removabletherefrom to allow access to the interior. A feeding-hopper a is mountedin the upper half a of the casing, said hopper having the adjustablefeed-regulating slide a (See Fig. 2.)

Mounted in boxes 13 on bearing-blocks b are two driving-shafts 0, eachof said shafts being provided with a driving-pulley 0. One of said boxesB is adjustable on the blocks 12 by means of shims b and adjusting-bolts19 as indicated in Fig. 1. Keyed to each of said shafts O are flangedhubs c, and as these hubs and their attached parts are alike inconstruction We will describe but one of them. One of the flanges of thehub is of less diameter than the other, the reason for which willpresently appear. Between the flanges of the hub c are radially-movableweights 0, pivoted to rods or pivot-bolts 0 passing through the flanges,said weights having slots 0 in them to allow radial movements.Surrounding said weights 0 and lying between the flanges of the hub c isa hard-steel tire D,which is slipped into place over the smaller flangeof the hub c and secured in place by means of a removable ring d, whichis bolted to the flange of the hub c, as clearly shown in Fig. 3. Thepivot-bolts c serve as stops to limit the outward movements of theweights 0 and also as positive connections between said weights and therotary hub 0, while the frictional pressure of the said weights againstthe loose tire D will cause the latter to rotate with the said hub c andits shaft with but little circular slip or lost motion. It is this tireD which When the directly to the roll-shafts.

mill is running and the roll-shafts are driven at high speed, theslotted weights 0 will be thrown outward by centrifugal force and,pressing against the inner side of the tire D, will force it toward thetire of the other crushing-roll or against the material between the tworolls. It will be seen from Fig. 2 that the weights 0 are effective onlyon the crushing side of the roll and press against the said tire D onlyon that side, the tire D having preferably an internal diameter equal tothe diametric extent of the radially projected Weights. When the rollsare relatively adjusted, as shown in Fig. 2, the tire D is cocentric toits roll-shaft, so that the weights 0 can, as above stated, only pressagainst the tire on the crushing side of the roll. In other words, theloose tire will when in crushing operation be forced into an eccentricposition relative to the shaft of its roll by the companion roll orcooperating crushing memberor by the material being crushed, while theweights 0 will have a constant tendency, to press said loose tire into acentral position relative to its roll-shaft.

Instead of the single solid crushing-tire D a series of narrow tires DD? D (see Fig. 4) may be employed, said narrow tires being locked inplace between the flanges in the same manner as the single tire. Withthis construct-ion of sectional tire sectional weights 0 may beemployed, if desired, so that one section of the tire may yield to undueresistance without arresting the crushing action of the other sections.This construction of roll, it will be seen, affords a continuouscircumferential but yielding crushing face, so that if the resistance ofthe material between the rollsbecomes greater than the crushing force ofthe outwardly-pressing weights the stress incident tocrushing isentirelyabsorbed by the tires and Weights and is not transmitted We are enabledbecause of this to make the shaft-bearings andmill-casing of muchlighter construction than is practicable where the crushing strain isborne by the shafts and mill-frame, and yet the crushing power oftherolls is not diminished because of this lighter construction.

The tires D, since they fitin the flanged hubs loosely, do not have tobe machined to insure a closefit, as is the case in the solidroll typeof mill, and we are able to use tires made of ,very hard metal, suchasmanganese steel, and capable of resisting wear for a long period.

The pressure of the weights 0 againstthe tires D of the crushing roll-orrolls, and which pressure results from centrifugal action when the rollor rolls are in rotation, is sufficient to prevent the tires fromslipping'seriously relative to the rotating shaftson which the rollsaremounted. It will be apparentthat one of said'crushing-rolls mightbedispensed with and a resisting member consisting of a stationary anvilor surface substituted therefor,and with which anvil or surface a singleroll of the construction hereinbefore described would cooperate, thematerial to be reduced being fed from the hopper between the said rolland the anvil-surface, and we do not wish to be understood as limitingourselves to the use of two rolls, as shown, or to the other detailsherein illustrated, since our invention resides in the novel type ofroll,,with out regard to the particular arrangement of cooperating partsor details of construction.

Having thus described our invention, we claim and desire to secure byLetters Patent- 1. In a crushing-mill, the combination with a resistingmember, of a crushing-roll comprising a shaft, a hub, a tire looserelative to said hub and affording a circumferential crushing-surface,and a series of weights located inside of said tire and tending, bycentrifugal action, to force the latter into a central position relativeto the said shaft of the said roll. I

2. In a crushing-mill, the combination with a resisting member,'of adriving-shaft, a hub fixed to said shaft, a tire loose in relation tosaid hub and affording a circumferential crushing-surface and a seriesof weights interposed between said tire and shaft and tending, bycentrifugal action, to force said tire into a central position relativeto said shaft. 7

3. In a crushing-mill, the combination with a yielding resisting member,of a drivingsha'ft, and a crushing-roll having a loose tire forming acircumferential crushing-surface, and a series of weights interposedbetween said tire and shaft and tending, by centrifugal action, to forcesaid tire toward said yielding resisting member.

4. In a crushing-mill, a rotating shaft, and

'a crushing-roll comprising a loose tire forming a circumferentialcrushing-surface, and a series of movable weights interposed betweensaid tire and said shaft, combined with a resisting member cooperatingwith said loose tire.

5. In a crushing-mill, a rotating shaft, and

a crushing-roll comprising a loosetire'forming .a tire looselymo'u'ntedbetween said flanges and affording a circumferential crushing-surface,and a series of weights interposed between saidtire and shaft andtending, by centrifugal action, to force said tire into a centralposition relative to said shaft.

7. In a crushing-mill, the combination with two rotatingshafts, of twocrushing-rolls each of which comprises a loosely-mounted tire and aseries of weights interposed between said tire and its shaft, saidweights tending, by cen= trifugal action, to force each loosely-mountedtire into a central axial position, when said shafts are in rotation.

8. In a crushing-mill, the combination with two rotating shafts, of twocrushing-rolls each of which comprises a loosely-mounted tire and aseries of weights interposed between said tire and its shaft, saidweights tending, by centrifugal actiomto force the loosely-mounted tiresof the two rolls into central positions relative to their shafts whenthe latter are in rotation, one of said rolls being mounted inadjustable bearings whereby its position relative to the other roll maybe varied.

9. In a crushing-mill, the combination with a rotating shaft, of a hubfixed to said shaft and provided with two separated flanges of unequaldiameter, a tire loosely mounted between said flanges, a series ofmovable weights interposed between said tire and shaft, and a removablering serving to hold the said tire in place after said tire has beenplaced in position by being slipped over the smaller of said flanges.

10. In a crushing-mill,the combination With a driving-shaft, of aflanged hub fixed to said shaft, a tire loosely mounted between theflanges of said hub, and a series of pivoted and inwardly and outwardlymovable weights mounted between the flanges of the hub and interposedbetween said tire and shaft.

11. In a crusl1ing-n1ill,the combination with a resisting member, of acrushing-roll having a loose tire affording a circumferentialcrushing-surface, a series of weights located inside 3 5 said tire andtending, when the said roll is in rotation, to force said tire into acentral position relative to the shaft of the said roll, and stops tolimit the outward movements of the said weights.

12. In acrushing-mill,the combination with a resisting member, of adriving-shaft, a hub fixed to said shaft, a tire loosely mounted on thesaid hub and affording a circumferential crushing-surface, a series ofweights inter- 45 posed between said shaft and tire, and stops servingto limit the outward movements of said weights and to connect the latterwith said shaft through said hub.

13. A roll comprising a shaft, a hub, a tire 5o loose relative to saidhub and a series of Weights located inside said tire and adapted to bepressed against the latter by centrifugal action as the said roll andweights rotate.

In testimony whereof we affix our signa- 55 tures in the presence of twoWitnesses.

THOMAS L. STURTEVANT. THOMAS J. STURTEVANT.

Witnesses:

W. H. ELLIS, FRED W. OoNNoLLY.

